Abstract: To explore the efficient cultivation of Paeonia ostii, a main cultivar of oil peony, and improve the efficiency of land and light utilization, we measured the microclimate of P. ostii monoculture (CK) and its intercropping systems with Carica papaya, Toona sinensis, and Juglans regiarespectively, and analyzed the photosynthetic characteristics (P_n) of P. ostii, the relationship between P_n and main eco-physiological factors, and differences among chlorophyll content and fluorescence parameters under the four cropping systems. The results showed that there were significant differences of microclimate among the four cropping patterns in June. Bimodal curves were presented in monoculture and P. ostii-C. papaya intercropping system, while unimodal curves were presented in P. ostii-T. sinensis and P. ostii-J. regia intercropping systems. The highest daily mean value of P_n was observed in P. ostii-J. regiaintercropping system, while the lowest value was in P. ostii-C. papayaintercropping system. The daily mean value of stomatal conductance (G_s) in P. ostii-C. papaya intercropping system was the lowest. The daily mean values of G_s and transpiration rate (T_r) in P. ostii-T. sinensis intercropping system were the highest, while the water use efficiency (WUE) was the lowest in this system. Results from the correlation analysis and multiple stepwise regression analysis showed that eco-physiological factors affectingP_n varied among intercropping patterns. Moreover, intercropping patterns also increased the chlorophyll content, F_m, F_v/F_m,Φ_PSⅡ, ETR and NPQ ofP. ostiileaves. Therefore, intercropping patterns, especiallyP. ostii-T. sinensis and P. ostii-J. regia intercropping, could guarantee normal photosynthetic production of oil peony and improve the utilization efficiency of land and light and increased biomass per unit land area, with generalized value of application.

Key words: B-G segmentation algorithm, ensemble empirical mode decomposition (EEMD), lag analysis, pollen monitoring